diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt
index b22b00b4c..8feea6b7f 100644
--- a/Documentation/user-manual.txt
+++ b/Documentation/user-manual.txt
@@ -1816,52 +1816,15 @@ from the _Media_ tab as well as the dive profile.
 
 By right-clicking on a video and selecting the "Save dive data as subtitles" option, a subtitles
 file with the same name as the video but with an ".ass" extension is created that contains
-time dependent dive data to be overlayed with the video. The format of the subtitle is specified
-in the _Media preferences_ (_File->Preferences->Media_). The tags used in the format string are
-replaced with the actual values, if present, or removed if not present in the data.
-The VLC video player automatically finds this file upon playing
-the video and overlays the dive data. Alternatively, the ffmpeg video encoder can be used to create a
+time dependent dive data (runtime, depth, temperature, NDL, TTS, surface GF) to be overlayed
+with the video. The VLC video player automatically finds this file upon playing the video
+and overlays the dive data. Alternatively, the ffmpeg video encoder can be used to create a
 new video file with the dive data encoded in the video stream. To do so run
 
 	ffmpeg -v video.mp4 -vf "ass=video.ass" video_with_data.mp4
 
 from the command line. You need to have the libass library installed.
 
-Available tags are:
-* Dive time: [time]
-* Depth: [depth]
-* Temperature: [temperature]
-* Ceiling: [ceiling]
-* NDL: [ndl]
-* TTS: [tts]
-* RBT: [rbt]
-* Stop time: [stoptime]
-* Stop depth: [stopdepth]
-* CNS: [cns]
-* SAC: [sac]
-* pO₂: [p_o2]
-* pN₂: [p_n2]
-* pHe: [p_he]
-* O₂ pressure (rebreather): [o2_pressure]
-* O₂ setpoint: [o2_setpoint]
-* SCR ΔpO₂: [scr_oc_po2]
-* MOD: [mod]
-* EAD: [ead]
-* END: [end]
-* EADD: [eadd]
-* Vertical speed: [speed]
-* In deco (calculated): [in_deco]
-* NDL (calculated): [ndl_calc]
-* TTS (calculated): [tts_calc]
-* Stop time (calculated): [stoptime_calc]
-* Stop depth (calculated): [stopdepth_calc]
-* Heartrate: [heartrate]
-* Bearing: [bearing]
-* Surface GF: [surface_gf]
-* Current GF: [current_gf]
-* Density: [density]
-* ICD Warning: [icd_warning]
-
 ==== Media on an external hard disk
 Most underwater photographers store media on an external drive. If such a drive can be mapped by the operating system
 (almost always the case) the media can be directly accessed by _Subsurface_. This eases the interaction
diff --git a/core/save-profiledata.cpp b/core/save-profiledata.cpp
index 893fdbe70..5715c698f 100644
--- a/core/save-profiledata.cpp
+++ b/core/save-profiledata.cpp
@@ -50,7 +50,7 @@ static std::string video_time(int secs)
 void replace_all(std::string& str, const std::string& old_value, const std::string& new_value) {
     if (old_value.empty())
         return;
-    size_t start_pos = 0;
+    size_t start_pos = std::string::npos;
     while ((start_pos = str.find(old_value, start_pos)) != std::string::npos) {
         str.replace(start_pos, old_value.length(), new_value);
         start_pos += new_value.length(); // In case 'new_value' contains 'old_value', like replacing 'x' with 'yx'